FR2594684A1 - Plaster cutter for freeing and ejecting pins (needles included in a plaster model intended to reinforce a dental preparation) - Google Patents

Abstract

The invention relates to a device for freeing and mechanically ejecting a dental preparation (die: dental preparation made of plaster reinforced with a metal needle, called a pin). It is a plaster cutter. It consists: - of a rod 1 having an orifice 16, - of a cutting head 9, - of a percussion unit 10-10 bis for variant B. Its function is to hollow out of the base of the plaster mould a regular ovoid bowl around the needle. Variants A and B furthermore allow the die to be ejected: - first by using the percussive effect of a handpiece, - the second by using the percussion system inside the cutter 10-10 bis. The device according to the invention is intended for professionals in dental prosthesis laboratories.

Description

 Plaster STRAWBERRY to clear the end of single (r) pines.

DESCRIPTION OF THE INVENTION
Fig. 2
This device according to the invention is intended to disengage by milling, the end of a needle (pins), holding a dental preparation, incorporated
porée in a plaster molding.

It consists :
1) a rod (1) of -35mm in length and 2.35mm in diameter, reinforced by a portion of 5mm (2), 5mm in length and 4mm in diameter
2) an oval-shaped milling head 12mm high and llmm in diameter in its widest part, in which are cut
sixteen helical shaped teeth (O) 0.5mm deep and 100 angled
- a tapered orifice (16) 4.5mm deep, having at its base 2.5mm in diameter and 1.8mm at its end
- three cylindrical vents (19) 7mm deep and 2mm in diameter
- a control stop (18) 5mm high
This device is made in one piece, in high speed steel (HSS) with trai
thermally vacuum, or tungsten carbide.

It is intended for dental professionals and particularly for
technicians in dental prosthesis laboratories.

Figure (1) shows the device as a whole.

Figure (2) shows the device in section.

 The preparation held by the needle (13) must be ejected later using a hammer.

(x) metal needle incorporated in a plaster molding
VARIANT TO THE INVENTION
Plaster STRAWBERRY fitted with a flange to release and eject the single pins (x).

The following device relates to a variant of the invention, making it possible to release and eject in a single time and mechanically, by effect of
tercussion, the needle holding the preparation.

DESCRIPTION OF THE A VARIANT OF THE INVENTION
Fig. 7
This device relates to a variant of the invention, making it possible to release and eject in a single time and mechanically, by percussion effect
sion, the needle (13) holding the dental preparation (die) I1 consists of:
1 of a rod (1) 35mm in length and 2.35mm in diameter, reinforced over a portion of 5zm 2) in length and 4mm in diameter
2 of an oval-shaped milling head (9) 12 mm high and 11 mm in diameter at its widest part, in which are cut
sixteen helocoidal teeth (0) 0.5mm deep and 10 'angled, composed of:
- a tapered orifice (16) 4.5mm deep, having at its base 2.5mm in diameter and 1.8mm at its end
- three cylindrical vents (19) 7mm deep and 2mm in diameter
- a stop (18) 5mm high
- a flange (20) 11mm in diameter and 1.2mm thick crimped hot or with liquid nitrogen.

This device is made of two parts - the rod and the cutter, monobloc, in high speed steel (HSS) with milking
thermal vacuum - the high-speed steel flange.

 This device can be used: - for milling only, with an ordinary handpiece - for milling and ejection, with a percussion handpiece.

This device is intended for dental professionals, particularly technicians of denture laboratories.
to hush up.

Figure 6 shows the device as a whole.

Figure 7 shows the device in section.

VARIANT B OF THE INVENTION
STRAWBERRY with internal percussion, to release and eject mechanically the Single Pins.

DESCRIPTION OF VARIANT B OF THE INVENTION
Fig. 11
Device allowing to mechanically release and eject a metal needle (Pins) incorporated in a plaster molding.

 Figure 11 shows the device as a whole.

 Figure 12 shows the device in section.

It consists of four parts: - a fixing part Fig 13 - a milling head Fig 14 - a percussion part Fig 15 - a spring (17) 1) The fixing part Fig 13
It is made of a single block of HSS high-speed steel

It is made up of:
- a rod (1) 35mm long and 2.35mm in diameter
- a reinforcement (2) 4mm high and 6mm in diameter, in which two sections (3) are cut necessary for clamping or loosening
rage on the milling part
- a locking shoulder (4) 0.8mm high and 9mm in diameter
- a thread (15) 2.5mm high and pitch M.8 x 0.5
- six teeth (6) lmm deep distributed at 60 ', necessary for percussion
- a bore (14a) 2mm deep and 4mm in diameter, in which the spring will be housed 2) The milling head Fig 14
It is made from a single block of HSS high-speed steel or preferably tungsten carbide.

It is made up of: - a cutter (9) 12n tall and 11mm in diameter, ovoid in its
end (bc), cylindrical in its lower part (ab), on which are cut sixteen helical teeth of 0.5mm deep
and 10. angle Fig. 16 and 17.

- a first bore (8) 7mm deep and 8mm in diameter, fitted
at its base with a thread (15) of pitch M.8 x 0.5 intended to receive the fixing part.

- a second bore (18) 3mm deep and 4mm in diameter,
these two bores being intended to receive the percussion assembly (10-10 bis).

- a third bore (11) with a conical shape of 2mm at its base and
2.3mm at its end - three vents (12) 1.8mm in diameter 3) The percussion part Fig. 15
It is made of a single block of HSS high-speed steel

It is made up of:
- a first cylinder (10) 4mm high and 7.9mm in diameter provided at its base with six teeth (7), of mm repaired depth
ties to 60,
- a bore (14) 2.5mm deep and 4mm in diameter in which the spring will be housed
- a second cylinder (10 bis) 3mm high and 7.9mm in diameter in which a decentered notch (16), 1.3mm is hollowed out
wide and 1.5mm deep.

4) The spring (17)
It is made up of: - a 5 / 10mm stainless steel wire - average diameter: 4.5mm outside diameter: 4.9mm - useful turns: around 4.5 - height: 7.1mm block height: 3.5mm - under load: 400 gr (+ 10%)
OPERATING PRINCIPLE
Invention Fig. 2
The operating principle of this plaster cutter is to dega
manage the single pins (i) incorporated in a plaster molding. Fig. 5
After having sawed off the proximal faces of the preparation,
the cutter (9) is fixed on a handpiece, it is placed in contact with
the plaster molding base and its frustoconical orifice (16) is
focused on the needle (13).

The mechanical rotation of the cutter leads to the formation of a cu
ovoid vette around the needle (13), plaster dust escaping
without stuffing thanks to the helical shape of the teeth fig.l and fig. 16
and the presence of the vents (19).

The needle release will be complete when its end is in
contact with the stop (8).

Currently, this work is done manually using gouges,
knives, etc ... or with milling cutters working laterally, in relation to
the needle (13), therefore irregularly.

Variant A Fig. 7
The operating principle of this plaster cutter is to release
and eject the simple pins incorporated in a plaster molding, according to the
variant A of the invention.

After obtaining the needle clearance (13), following the principle of function
tction of the invention, the stop (18) comes into contact with ltaiguil-
(13), the latter is ejected by percussion effect transmitted by a part
this percussion hand, the collar (20) limits the milling of the ca
ovoid, when it comes into contact with the molding base.

~ metal needle incorporated in a plaster molding
Variant B Fig. 12
The operating principle of this plaster milling cutter is to release and eject the simple pins incorporated in a plaster molding
according to variant B of the invention.

After obtaining the needle clearance (13), following the principle of
operation of the invention, the end of the needle (13) penetrates into the notch (16) and blocks the assembly (10-10bis), in rotation
thus generating the percussion effect.

The milling of the bowl continues, the pressure on the needle increases,
compressing the spring (17), until the percussion effect is sufficient to eject the die (*).

 At the end of the operation, the spring (17) relaxes and returns the percussion assembly (10-10bis) to its initial position.

 X dental preparation in plaster armed with a metal needle

Claims (6)

 1- Device for mechanically clearing the dies (s) of the plaster models during the  realization in the laboratory, of dental prostheses characterized in that it comprises a milling cutter Fig.2, presented  both a frustoconical orifice (11), centered on the end of the needle (13) to be released, which makes it possible to create an ovot cavity  of.  2- Device according to claim 1, characterized in that the shape of the cutter creates a shaped cavity  ovoid, symmetrical with respect to the needle (13), allowing easier access to the end of the die.  3- Device according to claim 1 characterized in that the plaster cutter Fig. 7 also has a stop (18).  4- Device according to claim 1 and claim 2, characterized in that the stop (18) allows to transmit the ef  percussion fet (given by a handpiece), at the end of the needle, and thereby eject the die.  5- Device according to claim 1 characterized in that the milling cutter Fig. 12 additionally has a percussion mechanism  sion included in the head of the cutter.  6- Device according to claim 1 and claim 3 characterized in that the internal percussion mechanism (10-10bis),  transset the percussion effect at the end of the needle (13) and therefore allows the die to be ejected. n dental plaster preparation armed with a metal needle (Pins)